Ventilation/Perfusion

1. Physiological Dead Space

1.1. Bohr's Equation

1.1.1. Dead space can't cause hypoxemia on its own

1.1.2. Dead space-->Hypercapnia-->increased RR

2. Alveolar Ventilation Equation

3. Alveolar Gas Equation

4. Lung Perfusion

4.1. Apex--Least

4.2. Base--highest

5. Lung Ventilation

5.1. Highest: Base

5.2. Lowest: Apex

6. ∆Perfusion (Base to Apex)>>∆Ventilation (Base to Apex)

7. Normal V/Q ratio (entire lung): 0.8

8. Pa>Pv>P(A): Zone 3

9. Pa>P(A)>Pv: Zone 2

9.1. Pulsatile Blood Flow

10. P(A)>Pa>Pv: Zone 1

11. Exercise

11.1. Increased O2 demand

11.2. Increased RR

11.3. Increased CO

11.4. V/Q ratio approaches 1

11.4.1. Increase in V> Increase in Q

11.4.2. Ratio becomes more even in zones